There is currently no easy-to-use technique available for designing, cutting and installing uniformly-fitting natural stone veneer components. Natural stone veneer, as the terra is used by those of skill in the art of cutting natural stone, is natural stone having an irregular or varied surface such that the natural stone veneer varies in thickness. Only manual, multi-step, labor-intensive methods are available for cutting and finishing the edges on natural stone veneer components. None of the current techniques offer the chance to preview the overall patterns of natural stone veneer components in advance of installation or amend a design before it is installed.
Starting with pallets of raw stone and cutting individual stones on a jobsite is an extremely time consuming undertaking that can prove challenging when managing a large project with tight deadlines. Further, typical techniques for dry-cutting natural stone at a jobsite generate potential health hazards from airborne stone dust, produce a messy work environment and cause damage to surrounding landscaping due to extended worker activity in the area. These environmental problems are of great concern particularly when the work is being done at an occupied residence or commercial location. Yet another time-consuming construction problem is achieving a style of stonework having the appearance of early New England fieldstone stonework. To achieve the appearance of this historical stonework, prior art methods require use of stones that have been naturally weathered and rounded over a period of many centuries by the action of water, weather and glacial movements. In building this style of stonework, the mason begins by selecting, from among many rounded stones, individual stones each having a size and fit such that each can be placed in the construction project in a way that results in the appearance of the stones as fitting tightly together. This is a very laborious process.
Because of the above-described difficulties, pre-cast artificial stone veneers are increasingly used in vertical applications such as residential exteriors, outdoor fireplaces and chimneys. Use of artificial stone veneer generally does not provide a means to preview the exact layout pattern of individual pieces prior to installation. Further, cutting artificial stones to fit around openings such as doors or windows, exposes unattractive cement aggregates.
Thus the need exists for improved methods of cutting natural stone and finishing the edges such that they appear to have been prepared using traditional chisel and hammer techniques when installed. There is also a need for producing natural stone components that require less skill to install than commercially available components that are either in rough form or approximately squared up, requiring additional cutting for installation.
Prior methods of cutting natural stone for veneer applications include using a hammer and chisel, hydraulic snapping equipment, large circular diamond blades to cut the stone or a combination of these techniques. Currently, some types of smooth, uniform-surfaced natural stone such as polished granite and marble countertop slabs or stone tiles used for floor inlays are cut with an abrasive waterier, from an abrasive waterjet machine. Abrasive waterjet cutting is a process that uses a mixture of high-pressure water and abrasive to cut material that is as soft, as styrofoam or as hard as titanium. However, prior to our discovery, there has been no method for practical or reliable use of a waterjet for cutting the rough, irregular surface common to veneer stone. To our knowledge, prior to our invention a waterjet has not been used to cut veneer stone.
It is generally known among those of skill in the art of stone-cutting, that the greater the distance from the stone surface that the cutting head of a waterjet is raised, the less precise is the resulting cut. The cut is rougher, i.e., less smooth. The higher the cutting head is raised off the stone surface, the lesser the force of the waterjet, producing wider cut and changing the geometry of the cut.
Prior to the disclosed methods, no one has drawn complete design plans for the actual cutting patterns of interconnecting veneer stone components for a project. The design of such projects has been determined in the field.
The terms “waterjet”, “waterjet machine”, and “waterjet cutting”, as used herein, will have the same meaning as “abrasive waterjet”, “abrasive waterjet machine”, and “abrasive waterjet cutting”, respectively.
The current way in which waterjets are actually used for cutting applications, and the methods of use of waterjets prescribed by manufacturers of such waterjet equipment in the directions and documentation provided with waterjet machines is to keep the waterjet as close as possible to the surface of the material being cut. Waterjets are intended to produce highly precise cuts on uniformly fiat material by keeping the head of the waterjet machine as tight as possible to the material being cut. The instructions of the manufacturer generally warn that if the waterjet is not kept close to the surface of the material, the pressure of the waterjet and the concentration of abrasive may be diminished such that the cut will not be clean or precise. Conventional practice in the waterjet industry places such a priority on maintaining a consistent, minimal standoff from the material being cut, that some companies have even developed systems for sensing gradual sloping curvatures over smooth material and adjusting the cutting head to maintain a minimal predetermined standoff. Other companies have developed programmable z-axis controls to be able to program the raising and lowering of the cutting head in relation to precise geometries of the material being cut, so as to maintain minimal standoff. The common factor is the attempt to run with the smallest possible standoff from the material so as to ensure the most precise cut, and the reduction of taper due to the dissipation of energy of the waterjet at increasing depth of cut. None of these systems are able to reliably navigate the extremely rough and irregular surfaces characteristic of the type of veneer stone described herein.